This invention pertains to an electrical connector and, in particular, a zero insertion force miniature grid array socket for integrated circuit packages such as ball grid arrays or pin grid arrays.
Integrated circuits (I.C.s) have become the world's standard for electronic circuits. These range from basic transistor networks to complex memory, microprocessor and multi-chip module circuits. The common denominator to all such circuits is that they are produced en mass on a substrate such as silicon and then separated into individual units commonly known as chips. The majority of chips are then mounted in a carrier for subsequent incorporation into end products. The basic size, shape and construction of the carrier is commonly known as the package and many standard packages have emerged. Some examples are commonly known as D.I.P.S.O.J., P.L.C.C., Q.F.P. and B.G.A. Chip packages have developed to accommodate both circuit function, i.e., number and placement of the leads, and assembly trends, i.e., thru-board and surface mount solder assembly. While the majority of I.C. devices are hard soldered in place, several factors such as device availability, testing, upgrades, etc., have traditionally shown that there is need to socket I.C.s, regardless of their package. In fact, I.C. sockets are known in the art for receiving pin grid array packages (PGA) on 0.100 inch.times.0.100 inch spacing. However, there are many miniature I.C. packages which have spacing less than 0.100 inch.times.0.100 inch. As I.C. packages become more miniaturized, it is desirable to socket these packages. It is the intent of this invention to provide a simple, economical, reliable and space-efficient socketing system, targeted for today's high pin count, miniature I.C. packages such as miniature grid array packages which include ball grid arrays (BGA) packages and pin grid array packages.
Accordingly, it is an object of the present invention to provide a socket which may intermate with various miniature I.C. packages.
It is another object of the present invention to provide a socket which intermates with a miniature grid array package.
It is a further object of the present invention to provide a socket having a footprint identical to the I.C. package mounted thereto.
It is a further object of the present invention to provide a surface mount socket.
It is also an object of the present invention to provide a socket which has no real estate penalty on a printed circuit board.
It is another object of the present invention to provide a socket having a zero insertion force.
It is another object of the present invention to provide a socketing system in which the I.C. package is not subject to reflow soldering.
It is a further object of the present invention to provide a socket which allows for inspectability and repairability of contact solder joints.
It is also an object of the present invention to provide a socket having a low profile.
It is a further object of the present invention to provide a socket which provides for metal-to-metal connections.
It is another object of the present invention to provide a socket having low self inductance.